Forcing her to have a termination, which as much as possible to her understanding, she does not want, because she won't be a good mother is barbaric.
That isn't why the termination is happening. It's because there is no outcome where she can have the baby and keep it, which means that, if she has the baby, either she has to leave her home, or she has to give the baby up for adoption - both of which would be considerably more distressing.
She could have an open adoption. Or if her thoughts and feelings on the matter are so insignificant, and it's ok to forcibly put her through extreme surgery and put a very developed and, to the best of her ability, wanted foetus to death, why are you bothered whether she's upset about adoption?
She has no understanding of this baby as a foetus. She has no understanding of labour, feeding, how she will be physically after a normal birth or a Caesarian. Essentially, she seems to want the baby in the same way she wants a doll, and unfortunately if the baby is born she can't have it.
People who know much more about the situation and, in particular, about this girl, than we do have decided that this is the least worst option for her. How do you claim to know better, PouncerDarling?